Amino - n - oxides as development accelerators in photography



United States Patent 3,532,499 AMINO N OXIDES AS DEVELOPMENT ACCELERATORS IN PHOTOGRAPHY Jozef Frans Willems, Wilrijk-Antwerp, Francis Jeanne Sels, Kontich, and Joseph Louis DeMunck, Heide- Kalmthout, Belgium, assignors to Gevaert-Agfa N.V., Mortsel, Belgium, a company of Belgium No Drawing. Filed Aug. 22, 1966, Ser. No. 573,801 Claims priority, application Great Britain, Oct. 7, 1965, 42,592/ 65 Int. Cl. G03c 5/30, 1/06, 1/48 U.S. Cl. 9666.3 7 Claims ABSTRACT OF THE DISCLOSURE Photographic light-sensitive silver halide emulsions containing an onium derivative of an amino-N-oxide are described. The onium derivatives of amino-N-oxides are development accelerators, extend the development latitude within normal developing times in which screen prints of good quality can be produced and do not fog.

This invention relates to the development of photographic silver halide emulsions in the presence of substances infiuencing the development and combinations of these substances with known development accelerators.

It is known that the development of continuous tone images by means of a hydroquinone p-N-methyl-aminophenol developer is accelerated under the influence of polyoxyalkylene compounds having a molecular weight preferably above 1500. When, however, such polyoxyalkylene compounds are used in combination with a hydroquinone-formaldehyde-bisulphite developer, as is known from the German Pat. No. 1,141,531 filed Jan. 24, 1962 by Perutz Photowerke G.m.b.H., an increase of the gradation together with a desensitisation is obtained. The latter combination is found to be very suitable for the development of light-sensitive materials suited for use in the graphic art on account of the very contrasty development obtained therewith.

It is also known that the development retardation caused when using the combination of polyoxyalkylene compounds with the above-mentioned type of developer can be counteracted and that the initial rate of development can be raised by using quaternary ammonium salts in conjunction with the above combination. It is, however, also known that quaternary ammonium compounds, when used in photographic emulsion layers tend to increase the fog considerably.

An enhanced initial rate of development and a development interval as long as possible in which sharp screen dots can be obtained yet, are of importance in practice for the development of graphic reproductions.

It has been found now that onium derivatives of amino- N-oxides and more particularly compounds according to the following structural formulae:

3,532,499 Patented Oct. 6, 1970 wherein:

each of R and R represents an alkyl radical e.g. methyl, an aralkyl radical e.g. benzyl, or together represent the atoms required for completing an heterocyclic ring e.g. a morpholine, a pyrrolidine, or a piperidine ring,

R represents an alkyl radical e.g. ethyl or an aralkyl radical e.g. benzyl,

R represents alkyl and aralkyl,

R represents a hydrogen atom or a substitutent such as an alkyl radical or an aralkyl radical,

X- represents an anion,

R represents a bivalent organic radical such as an alkylene radical or an alkylenephenylenealkylene radical, and

Z represents the atoms required for forming an heterocyclic ring system,

are not only very efiicient development accelerators by themselves, but they also considerably increase the initial rate of development of a developer combination comprising hydroquinone and polyoxyalkylene compounds and extend the development latitude within normal developing times, in which screen prints of good quality can be produced.

Compounds corresponding to one of these general formulae are i.e. the compounds resulting from the alkylation of tertiary amino-N-oxides such as trimethylamino- N-oxide, triethylamino-N-oxide, tributylamino-N-oxide, monomethyldiethylamino- N oxide, dodecyldimethylamino-N-oxide, cetyldimethylaminio-N-oxide, pyridine-N- oxide, a-, 5-, or 'y-picoline-N-oxide, chloropyridine-N- oxide, quinoline-N-oxides, lepidine-N-oxides, and amino- N-oxides derived from other heterocyclic nitrogen compounds.

Suitable alkylating agents are, e.g., alkyl bromides, alkyl tolusulphonates, alkylmethyl sulphonates, aralkyl bromides, 1,2-dibromomethane, 1,4-dibromobutane, p-xylylene dibromide, N,N'-bis-(2-bromoethyl)-succinamide, bis-(2-bromoethyl)-sulphone, bis (2 bromoethyl)-sub phide, bis (2 bromoethyl) ether, and N,N-bis-(10- bromohendecanoyl -ethylenediamine.

3 By way of illustration the preparation of some of the compound according to the above general formulae will now be described.

Preparation 1 OH. CH In a 250 cm. flask fitted with a condenser 0.25 mole of ethylene dibromide is mixed with 0.5 mole of fl-picoline-N-oxide in 150 cm. of ethanol. After refluxing for hours the solvent is evaporated in vacuo. The residue is recrystallised from a mixture of ethanol and tetrahydrofurane (:50). Melting point: 170 C. (decomposition).

Preparation 2 In a 250 cm. flask fitted with a condenser 0.25 mole of ethylene dibromide is mixed with 0.5 mole of 'ypiC0- line-N-oxide in 150 cm. of ethanol. After refluxing for 13 hours the solvent is evaporated in vacuo. The residue is recrystallised from a mixture of ethanol and tetrahydrofurane (50:50). Melting point: 170 C. (decomposition).

Preparation 3 In a 250 cm. flask fitted with a condenser 0.25 mole of ethylene dibromide is mixed with 0.5 mole of a-picoline-N-oxide in 150 cm. of ethanol. After refluxing for 15 hours the solvent is evaporated in vacuo. The residue is washed with acetone and then recrystallised from its 95% solution of ethanol. Melting point: 230 C. (decomposition).

Preparation 4 In a 100 cm. flask fitted with a condenser 0.05 mole of tetrarnethylene dibromide is mixed with 0.12 mole of triethylamine-N-oxide in 15 cm. of acetone. After having been refluxed for 5 hours the precipitate is filtered by suction and Washed with chloroform and afterwards with ether. Melting point: explodes on the Kofler hot bench at 200 C.

Preparation 6 In a 100 cm. flask fitted with a condenser 0.1 mole of dodecylmethyl sulphonate is mixed with 0.1 mole of pyridine-N-oxide in cm. of acetonitrile. After refluxing the solution for 6 hours, the solvent is evaporated in vacuo and the waxy residue is washed with ether.

Preparation 7 @rr-ogorrmc 13131011350 4 In a cm? flask fitted with a condenser 0.05 mole of hexadecylmethyl sulphonate is mixed with 0.05 mole of pyridine-N-oxide in 70 cm. of acetonitrile. After refluxing the solution for 6 hours, the solvent is evaporated in vacuo and the waxy residue is washed with ether.

Preparation 8 In a 100 cm. flask fitted with a condenser 0.1 mole of hexamethylene dibromide is mixed with 0.2 mole of pyridine-N-oxide in 40 cm. of acetonitrile. After having been refluxed for 2 hours the formed precipitate is filtered by suction. The precipitate is recrystallised from ethanol. Melting point: 162 C.

Preparation 9 In a 100 cm. flask fitted with a condenser 0.1 mole of n-hexylmethyl sulphonate is mixed with 0.1 mole of pyridine-N-oxide in 50 cm. of acetonitrile. After refluxing the solution for 6 hours, the solvent is evaporated in vacuo and the waxy residue is washed with a mixture of ether and ethyl acetate (50:50).

Preparation 10 -In a 100 cm. flask fitted with a condenser 0.1 mole of n-octylmethyl sulphonate is mixed with 0.1 mole of pyridine-N-oxide in 50 cm. of acetonitrile. After refluxing the solution for 6 hours, the solvent is evaporated in vacuo and the waxy residue is Washed with ether.

Preparation 11 In a 100 cm. flask fitted with a condenser 0.1 mole of n-decylmethyl sulphonate is mixed with 0.1 mole of pyridine-N-oxide in 50 cm. of acetonitrile. After refluxing the solution for 6 hours, the solvent is evaporated and the waxy residue is Washed with ether.

The product according to the formula:

is prepared as described in J. Org. Chem. 22 (1957) p. 1135. The product according to the formula:

is prepared as described in J. Chem. Soc. (1956) p. 2407. The following products are prepared as described in Acta Chem. Scand. 17 (1963) p. 953:

Hz 0 Ha The onium derivatives of the amino-N-oxides influencing the rate of development are preferably added to the light-sensitive silver halide emulsions in dissolved form in water or a mixture of water and water-miscible organic solvents, which do not impair the photographic characteristics of the emulsion.

However, these condensation products can also be incorporated into the emulsion by im'bibition by treating it with a solution containing these products or by d ffusion from an adjacent water-permeable layer comprising these products.

The onium derivatives of the amine-N-oxides used according to the present invention can be added to the light-sensitive silver halide emulsion during different preparation steps of the light-sensitive material. For example they can be incorporated therein by a separate addition or they can be added as a mixture with one or more ingredients used in the formation of the silver halide grains, during the physical or chemical ripening or during another step preceding the coating of the emulslon. For the purpose of increasing the gradation and accelerating the development the said derivatives are preferably used in combination with -water-soluble alkylene oxide condensation products as described e.g. in the United States patent specifications 1,970,578 by Conrad Schoeller and Max Wittwer issued Aug. 21, 1934, 2,240,472 by Donald R. Swan issued Apr. 29, 1941, 2,423,549 by Ralph K. Blake, William A. Stanton, Ferdinand Schulze issued July 8, 1947, 2,441,389 by Ralph K. Blake issued Mar. 11, 1948, 2531,832 'by William A Stanton issued Nov. 11 1950, 2,533,990 by Ralph K. Blake issued Dec. 12, 1950 and the British patent specifications 920,637 filed May 7, 1959 by Gevaert Photo-Producten N.V., 940,051 filed Nov. 1, 1961 by Gevaert Photo-Producten N.V., 945,340 filed Oct. 23, 1961 by Gevaert Photo-Producten N.V., 991,608 filed June 14, 1961 by Kodak and the Belgian patent specification 648,710 filed June 2, 1964 by Gevaert Photo-Producten NV.

The polyoxyalkylene compounds i.e. alkylene oxide condensation products together with the onium derivatives of the amine-N-oxides as described above can be added to the composition of the silver halide emulsion of to a water-permeable layer, which together with the emulsion layer forms part of a water-permeable element.

The said derivatives are preferably added to the emulsion after the chemical ripening and just before the coating of the emulsion.

The alkylene oxide condensation products and/or the onium derivatives of the amine-N-oxides can also be added to the developing bath.

The optimum amount of alkylene oxide condensation product and onium derivatives of amine-N-oxides according to the above formulae depends on the very compound, on the nature of the colloid binder of the silver halide grains and on the amount and type of silver halide in the emulsion. In general, however, the above alkylene oxide condensation products are added to the light-sensitive material in an amount of mg. of 10 g. per mole of silver halide. When incorporated into the developer they are used in amounts ranging from 100 mg. to 10 g. per litre of developer. The amount of onium derivative incorporated into the light-sensitive material preferably ranges between 5 mg. and 5 g. per mole of silver halide. When added to the developing bath the derivative is used preferably in an amount varying between 5 mg. to 5 g. per litre.

The development acceleration and the increase of dot definition and of the development latitude obtained with the products according to the present invention can be combined with a chemical sensitisation by using in combination with the above-mentioned onium derivatives of amine-N-oxides chemical sensitising agents such as sulphur-containing compounds e.g. allyl isothiocyanate, allyl thiourea, or sodium thiosulphate, reducing agents such as the tin compounds described in the Belgian patent specification 493,464 filed Jan. 24, 1950 and 568,687 filed June 18, 1958 by Gevaert Photo-Production, N.V., the iminoaminomethane sulphinic acid compounds described in the British patent specification 789,823 filed Apr. 29, 1955 by Gevaert Photo-Producten N.V., or precious metal compounds such as gold, platinum, palladium, iridium, ruthenium, and rodium compounds. The sensitising action also manifests itself of course, when combining the above-mentioned condensation products with the sensitising compounds present by nature in gelatin.

The products influencing the development according to the present invention can also be used in combination with stabilising agents for silver halide emulsions, such as mercury compounds and the compounds described in the Belgian patent specifications 571,916 and 571,917 both filed Oct. 10, 1958 by Gevaert Photo-Producten N.V., and in combination with sensitising and stabilising cadmium salts in the light-sensitive material as well as in the developer.

The onium compounds of amine-N-oxides either or not in combination with polyoxyalkylene compounds may be used to improve the developing characteristics of various types of emulsions. So, they may be used in combination with optically sensitised emulsion as well as with not optically sensitised emulsions e.g. X-ray emulsions as well as orthochromatic and panchromatic emulsions, and emulsions sensitive to infrared radiation. Various silver salts may be used as light-sensitive salt e.g. silver bromide, silver iodide, silver chloride, or mixed silver halides such as silver chlorobromide or silver bromoiodide. Said compounds may be used in emulsions for colour photography, emulsions of the mixed packet type, or emulsions of the mixed grain type. They can also be used in emulsions, which form latent images predominantly on the surface of the silver halide crystal, or in emulsions, which form latent images predominantly inside the silver halide crystal. They may be used in silver halide emulsions for application in the silver halide diffusion transfer process or other transfer processes based on silver halide photography, in which e.g. the diffusion of a developer, a coupler, or a dye is applied.

Together with the above-mentioned products, derivatives of tetra-azaindenes having the following general for- 7 8 mula can be used as fog-inhibiting compounds in the Boric acid g. light-sensitive material: Potassium bromide-0.5 g.

OH Water to1 litre. N The sensitometric results stated in Table 1 present a 5 clear picture of the development acceleration. Rz-(il TABLE 1 N/ Added amount in wherein: -p k p e a I I 10 of emulsion 1.1:. of each of R 1 and R 2 represents a hydrogen atom, an alkyl, g ggi g 0t regg gg abovgflfgg Gamma g an aralkyl, or an aryl rad1cal, and R' represents a hydrogen atom, an alkyl, 21 carboxy, or ii an alkoXycafbonyl p 11- 331 1.15 0. 50 0.09

Such compounds can be prepared by starting from 1 15 6 359 mole of fl-ketoester of an u-ethoxymethylene-fi-ketoester with 1 mole of a suitable 3-amino-l,2,4-triazole. By way EXAMPLE 2 0f p 0f Such derivative Y Y Test strips with a light-sensitive silver halide emulsion )'PY can be mentionedof the positive type (average grain size: 0.35 compris- Other agents such as hardening agents, Wetting agents, ing 98 111015 percent of silver bromide and 2 mole per- Plasticisers, developing agents, Optical Sensitising agents, cent of silver iodide) are exposed in identical conditions and binders Such as gelatin, latices, can be 'P and developed for different times in a solution having the rated into the emulsion in the usual Way. f n i i i The combination of the alkylene oxide derivatives in- 95 fluencing the development and onium derivatives of amine- Sodium heXametaphOSphat-e 1 N oxides according to the present invention can prefer- Anhydrous sodium sulphite 20 ably be used in the development of silver chloride and Anhydrous Sodium carbonate 20 silver bromochloride emulsions with a hydroquinone-formpotassium bromide 5 aldehyde-bisulphite developer. Hydmquinone 4 4 The following examples illustrate the invention.

The development accerelators listed in Table 2 are EXAMPLE 1 added to samples of this solution. The table also de- A washed gelatin silver iodobromide emulsion (94.5 notes the densities obtained after different development mole percent of silver bromide and 5.5 mole percent of times.

TABLE 2 Added Density obtained after dea nount veloping for in mg. Onium compound according to the formula per litre 15 sec. 30 see. sec. 60 sec.

silver iodide), (average grain size of the silver halide: EXAMPLE 3 0.8g) of the negative type is ripened at 45 C.

The emulsion ready for coating contains per kg. g. of silver halide, 75 g. of gelatin, 30 mg. of optical sensitising agent according to the following structural for- The amounts of compounds influencing the develop- 50 ment, defined in Table 3, are added before the coating step to samples of a green-sensitised gelatin silver chlorobromide emulsion (35 mole percent of bromide) commula' CH prising 5-methyl-7-hydroxy-s-triaz0lo-(l,5-a)-pyrimidine,

S I 3 s cadmium chloride and 25% by weight of a latex plasticizer calculated on the weight of gelatin. The latex-plasticizer H Brconsists of a latex of a 20% by Weight aqueous dispersion N+ N of poly(ethyl acrylate) prepared according to known (Q2115 (132m techniques of emulsion polymerisation by carrying out the polymerisation in the presence of 8% by Weight (calculated on the monomer) of an emulsifying agent 50 of s'methyl 7 hydloxy's'tnazolo(15a)- of one of the followin types the condensation g product the of triacetate support and dried. Other test strips are prei i or i Sodmm salt an alkyibenzene pared by adding to samples of the above-mentioned emulg g 2 gg; g z z the alkyl radlcal contams from sions prior to the coating step the development accele- Subse 32 thne'mulsion Stri s are harden d rators in the amounts listed in the table hereinafter. formaldghyde yeach time applied the Same: a a

i 5 22; :253:23: 2223 3232 3; zgs g i ggfifi cellulose triacetate support, and dried. They are exposed the following Solution: then through a continuous Wedge and a glass screen to 1 light With a colour temperature of 3700 K. The ex- Water--8OO cm. posure is regulated so that the wedge print of the screen Monomethyl-u-aminophenol sulphate2 g. includes the beginning of dot formation as well as the Hydroquinone-5 g. disappearance of the high lights.

Anhydrous sodium sulphite-100 g. The dot sharpness is judged of visually by comparison Borax-4O g. to standard materials, which is decreasing value of dot 9 sharpness quality are defined with the numbers 1, 2, 3, and 4.

Development is carried out at 19 C. in a developing bath comprising:

G. Sodium bisulphite 1.5 Hydroquinone Formaldehyde bisulphite Anhydrous sodium carbonate X represents an anion,

R represents a bivalent organic radical such as an alkylene or an alklene-phenylene-alkylene, and

Z represents the atoms required for forming a pyridine or quinoline nucleus.

2. A photographic light-sensitive silver halide material containing an onium derivative of an amino-N-oxide corresponding to one of the following structural formulae:

R1 Anhydrous sodium bicarbonate l5 1 Potassium bromide 1 7 Water to 1000 cmfi. R3

TABLE 3 Development time (in min.) Dot definition Mg. per 1.5 2.5 3.5 Development mol of time (in min.)

silver Compound halide 1 Speed Fog '7 Speed Fog 7 Speed Fog 1. 2. 5 3. 5

3. 9 24 0. 01 6. 7 87 0.01 5. 7 100 0.01 1 2 4 Polyethylene glycol having an average mol. weight of 2,000..-. 120 10 12 0. 01 10 47 0. 01 10 62 0. O1 4 4 1 A mixture of compound A 120 and 10 35 0. 01 10 60 0. 01 10 76 0. 01 1 1 1 A mixture of compound BL A mixture of compound A 120 and 10 32 0. 01 10 65 0. 01 10 80 0. 10 1 1 1 The compound prepared according to preparation 4.. 200 A mixture of compound A 120 and 10. 5 0. 01 9. 4 81 0. 01 8. 4 107 0. 01 3 1 2 The compound prepared according to preparation 200 N 0'rE.-The relative speed is expressed on a percentage basis, the exposure value having been measured at a density 3 above fog value.

prepared from 2 mole of methoxypolyethylene glycol and 1 mole of OCN(CHz)g-1NCO.

We claim:

1. Process for developing photographic materials containing a light-sensitive silver halide wherein the development is carried out in the presence of an onium derivative of an amino-N-oxide corresponding to one of the following structural formulae:

wherein each of R and R represents an alkyl radical, an aralkyl radical, or together the atoms required for completing an heterocyclic ring,

R represents an alkyl radical or an aralkyl radical,

R represents an alkyl radical or an aralkyl radical,

R represents a hydrogen atom, an alkyl radical or an aralkyl radical,

wherein according to claim 2, containnig in addition to an onium derivative of an amino-N-oxide a polyoxyalkylene compound.

4. A photographic light-sensitive silver halide material according to claim 3, containing in addition to an onium derivative of an amino-N-oxide a polyoxyalkylene compound and a fog-inhibiting compound of the following general formula:

1 1 12 each of R' and R' represents a hydrogen atom, an derivative is present in a developing bath in an amount alkyl, aralykl or aryl radical, and varying from 5 mg. to 5 g. per litre. h R 3 represents a ydrogen atom, an alkyl, a carboxy, References Cited or an alkoxycarbonyl group. 5. Process according to claim 1, wherein an onium UNITED STATES PATENTS derivative is present in the light-sensitive material in a 5 3,129,100 4/1964 Grabhisfer et range of 5 mg. to 5 g. per mole of silver halide.

6. The silver halide material according to claim 3, NORMAN TORCHIN, Primary Examiner wherein the polyoxyalkylene compound is present in the FOKELLEY Assistant Examiner light-sensitive material in an amount ranging from 100 10 mg. to 10 g. per mole of silver halide. US. Cl. X.R;

7. Process according to claim 1, wherein an onium 96-95 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 532, 499 Dated October 6, 1970 Jozef Frans Willems, Francis Jeanne Sels and Joseph Louis DeMunck It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Inventor Column 2, line 52, "cetyldimethylaminio" should read cetyldimethylamino Column 3, line 2, "compound" should read compounds Column 5, third formula set forth as CH CH N 2Br shou d rea Q r CH 7 CH line 60, "Mar." should read May Column 6, line 55, "emulsion" should read emulsions Column 7, line 72, "Monomethyl-u-aminophenol" should read Monomethyl-p-aminophenol Column 8, line 31, "accerelators" should read accelerators Table 2, under the heading "45 sec. "0. 65" should read 0. 05 Column 9, Table 3, column 2, line 4, insert 200 Table 3, column 1, last line after "preparation" insert 8 line 30, the formula set forth as should read H C O- (CH CH O) -CH -CH OOC-l IH Column 10, line 1, "X should read X' claim 2, formula 5 set forth as Y N- should read Z N- C C 1'1 ii claim 3, line 2, "containning" should read containing Signed and sealed thiq "71m fln'y nfm g lza (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents FORM PO-IOSO (10-69) ulcOMM-DC 00178-P60 t 0.1. aovummn nnmvn on. m o-awau 

